解决卡怪

[FIX] - fix creature go and back loop if it has spell

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bug description1:
if a creature has spell and this spell doesn't need casttime,it may be go to target and backward again and again

bug description1:
if you are warlock,you have called Voidwalker,you open auto cast spell at pet control panel,and then you select a target,click attack at pet control panel，the Voidwalker will go and back(loop)

Code:
Index: game/AIInterface.cpp
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--- game/AIInterface.cpp        (revision 670)
+++ game/AIInterface.cpp        (working copy)
@@ -901,6 +901,7 @@
                                        return;  // this shouldnt happen

                                /* stop moving so we don't interrupt the spell */
+                                if(m_nextSpell->spell->CastingTimeIndex != 1)
                                StopMovement(0);

                                float distance = m_Unit->GetDistanceSq(m_nextTarget);